Hydrodeoxygenation of isocyanates : snapshots of a magnesium-mediated C=O bond cleavage

bibtex: ISI:000400553000027 bibtex\location:'THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND',publisher:'ROYAL SOC CHEMISTRY',type:'Article',affiliation:'Fang, J (Reprint Author), Lanzhou Univ, Sch Chem & Chem Engn, Key Lab Nonferrous Met Chem & Resources Utilizat, Lanzhou 730000, Peoples R China. Hill, MS (Reprint Author), Univ Bath, Dept Chem, Bath BA2 7AY, Avon, England. Yang, Yan; Fang, Jian, Lanzhou Univ, Sch Chem & Chem Engn, Key Lab Nonferrous Met Chem & Resources Utilizat, Lanzhou 730000, Peoples R China. Anker, Mathew D.; Mahon, Mary F.; Weetman, Catherine; Hill, Michael S., Univ Bath, Dept Chem, Bath BA2 7AY, Avon, England. Maron, Laurent, Univ Toulouse, LPCNO, INSA Toulouse, 135,Ave Rangueil, F-31077 Toulouse, France.','author-email':'fangj@lzu.edu.cn msh27@bath.ac.uK',da:'2018-12-05','doc-delivery-number':'ET8MH',eissn:'2041-6539','funding-acknowledgement':'EPSRC (UK); University of Bath','funding-text':'We thank the EPSRC (UK) and the University of Bath for funding of studentships for CW and MDA.','journal-iso':'Chem. Sci.','keywords-plus':'ALKALINE-EARTH CATALYSIS; SELECTIVE REDUCTION; SECONDARY AMIDES; HYDROBORATION; AMINES; CARBONYL; DERIVATIVES; TERTIARY; CARBOXAMIDES; CHEMICALS','number-of-cited-references':'51',oa:'DOAJ Gold','orcid-numbers':'Weetman, Catherine/0000-0001-5643-9256 Anker, Mathew/0000-0003-0414-7635 Hill, Michael/0000-0001-9784-9649','research-areas':'Chemistry','researcherid-numbers':'Weetman, Catherine/O-3395-2018','times-cited':'4','unique-id':'ISI:000400553000027','usage-count-last-180-days':'6','usage-count-since-2013':'39','web-of-science-categories':'Chemistry, Multidisciplinary'\; International audience; Organic isocyanates are readily converted to methyl amine products through their hydroboration with HBpin in the presence of a beta-diketiminato magnesium catalyst. Although borylated amide and N-,O-bis(boryl)hemiaminal species have been identified as intermediates during the reductive catalysis, the overall reduction and C-O activation is metal-mediated and proposed to occur through the further intermediacy of well-defined magnesium formamidato, formamidatoborate and magnesium boryloxide derivatives. Examples of all these species have been identified and fully characterised through stoichiometric reactivity studies and the stability of the borate species leads us to suggest that, under catalytic conditions, the onward progress of the deoxygenation reaction is crucially dependent on the further activation provided by the Lewis acidic HBpin substrate. These deductions have been explored and ratified through a DFT study.